Transport through T-shaped quantum wires under potential modulation: Lattice Green’s function approach

By developing the lattice Green's function approach, we study transport properties of T-shaped quantum wires (TQWR) under potential modulation. It is found that the potential barrier in the vertical arm induces a dip-peak structure in conductance straight through and around the bend. The increase of potential thickness results in the dip-peak couples being more pronounced, while the number of dip-peak couple also increases with the thickness. The dip-peak structures are related to the quasibound states localized at the junction of the TQWR. We numerically analyze the dependence of the quasi-bound state energy on the potential height and width. Different conductance profiles can be selected by the potential modulation on coupled TQWR.